Industrial gas turbine power plant control system having capability for effectuating automatic fuel transfer under load preferably employing a digital computer

ABSTRACT

A gas turbine power plant is provided with an industrial gas turbine capable of sustained operation on either gas or liquid fuel or a mixture of the two. One or more of such turbinegenerator plants are operated by a hybrid digital computer control system during all turbine operating modes. Automatic transferring from operation using one fuel to operation sustained entirely by the other is achieved by computer directed dual fuel subsystem operation. Operation on a mixture of fuels is likewise computer directed.

United States Patent 1191 5/1968 French 60/3928 COMBUST'OR PRESSURE SENSOR BLADE PATH T VIBRATION HAUST T DISC CAVITY T CONSOLE AIR 1' ssusons pg FROM PLANT E FROM PLANT B POWER FOR CONTROL 8 SPE ED CONTROL OUT SYS CENTRAL DEVICES LOG PRINTER 'Reuther 1 Nov. 11, 1975 [5 1 INDUSTRIAL GAS TURBINE POWER 3.469395 9/1969 Spitsbergen 60/3928 PLANT CONTROL SYSTEM HAVING 3,482,396 12/1969 Nelson et :11. 60/3928 CAPABILITY FOR EFFECTUATING $52? AUTOMATIC FUEL TRANSFER UNDER 3:606:754 9/1971 Whit e IIIII Bo/39.28 LOAD PREFERABLY EMPLOYING A 3,643,437 2/ 1972 Brinbaum 290/40 DIGITAL COMPUTER 3,678,691 7/1972 Shohet 60/3928 3.688.495 9/1972 F hl 60/3926 [75] Invent: Reuther, plttsburgh 3.733.816 5/1973 N ash et al 60/3928 [73] Assignee: Westinghouse Electric Corporation,

1 Pittsburgh. Pa. 7 I Primary E.\'ami.'zer-G. R. Simmons 1972 Attorney, Agent, 01' Firm-S. A. Seinberg [21] Appl. No.1 308,892

[44] Published under the Trial Voluntary Protest Program on January 28, 1975 as document no. B 308,892 [57] ABSTRACT Related Applimtion Data A gas turbine power plant is provided with an indus- [63] Continuation of Ser. No. 205.263, Dec. 6, 1971. trial gas turbine capable of sustained operation on either gas or liquid fuel or a mixture of the two. One or [52] US. Cl. 322/15; 290/40; 60/3928; more of such turbine-generator plants are operated by 235/151.21 a hybrid digitalcomputer control system during all [51] Int. Cl. H02P 9/04 turbine operating modes. Automatic transferring from [58] Field of Search 60/3928, 39.27, 39.29; operation using one fuel to operation sustained en- 290/40, 40.1, 2; 322/14, 15, 38; 235/151.2l tirely by the other is achieved by computer directed dual fuel subsystem operation. Operation on a mixture [56] References Cited of fuels is likewise computer directed.

UNITED STATES PATENTS 3,382,672 9 Claims, 41 Drawing- Figures US. Patent Nov. 11, 1975 Sheet 1 of 33 3,919,623

FIG.I.

Sheet 3 of 33 3,919,623

U.S. Patent Nov. 11, 1975 NQN OVN ww M 5 "H 1. w r

Omm mvw mvm 09 S. m QE U.S. Patent Nov.11, 1975 Sheet40f33 3,919,623

IGNITION SYSTEM FIG 6 FIG' 5 Sheet 6 of 33 US. Patent Nov. 11, 1975 U.S. Patent Nov. 11, 1975 Sheet 10 0f33 3,919,623

US. Patent Nov. 11, 1975 Sheet 12 of 33 TIME DESIRED VAL E SETTER I00% 7 -L' LQH Ml! E B DESIRED VALUE 1 SETTER (MIX ONLY) GAS on.

LOLIMc ALL SETTERS=O% DESIRED VALQE SETTER 0% GAs L TRANSFER LOIl- 6-- [6 (MAXI5.7

q 5 8 0 Q Lu 0 (I) LU |J F 4-- 5, -4 G a I; 5 S 3-- ,3 -35 L1. O. 2 0 *5 FIG. I4

o L) 2.9 2 |O4%lDL 3 (L675) 3 START/I: --I VALVE OPEN I I m (I24) l.24-: g g IGNITION 0 I I I' i 0 (5|?) 0 I 2 3 4 s CONTROL SIGNAL OUTPUTV.D.C.

(MAX) 5| I04% IDLE I5-- BREAK POINT II.I Ta

IGNITION 6.4-

O I I I 4 CONTROL SIGNAL OUTPUTV.D.C.

PUMP DISCHARGE PRESS (PS ALL SETTERS IOO% FIG. I3

FIG. I5

US. Patent Nov. 11, 1975 Sheet 13 0933 3,919,623

f r x E O j k J WAT-[SI |.VARS-| GEN.

FREQ D.C.FLD. D.C. FLD. RUN BUS INC. GEN. TEMP. AMPS. VOLT VOLT voLT 52G 52G E E 2kg: g i GEN. BKR, GEN. BKR. B Q TRIP CLOSE CLOSE IIIMIE T2122 $225 l RAISE LowER START START START RESERVE 7 a 9 IO II I2 I3 I4 l5 l6 FIG. IGA I VOLT VOLT REG. REG.

RAISE LowER MANUEL AUTO.

OFF

52L 52L ON SYNC. LINE LINE SYNC.

OFF BKR. BKR. ON

TRIP CLOSE 23 24 25 26 27 2s 29 so TURBINE TURBINE READY MASTER AUx. TO LUBE TURN NG LUBE AUX. TRIP TO coNTRoL PUMP PRESS GEAR PRESS RESET RESET START ON ON 63 PS4 ON 63 PSI U.S. Patent Nov. 11,1975 Sheet 14 0f33 3,919,623

AUTO MANUEL SYNC. SYNC SYNC. SYNC. LIGHT LIGHT FIG. I68 I SELECT sELEcT mono. DEV.

HOLD e0 22 56 3! 32 33 34 s1 s2 63 e4 START 0.3 0.5 FLAME FLAME START DEVICE TRiP TRIP FUEL COMB. COMB. DEV. ON VALVE PRESS ON 6 7 OFF U.S. Patent Nov. 11, 1975 Sheet 16 of 33 |vOLTs AMPS FUEL DIFC I EXHA BLADE OONT. cAv. TEMP. TEMP TURBINE TURBINE NORMAL EMERG.

STOP START I TURBINE ALARM ggfi SHUT- HORN ALARM LAMP ALARM DOWN s ENcE REsET TEST ALARM I GAS OIL FIG. I6C GAS OIL FUEL & FUEL FUEL LOW GAS ONLY ONLY PRES. MIX

TRANsF.

GAS TURB LOCAL REMOTE TERfIQJSSg-T DEMAND EMERGENCY CON OL CON ROL REvIEw TR T NORMAL STOP AUX. 4I BLEED SYNC GEN. PUMP FLD. vALvE SPEED BKR. OFF BKR. OLOsED 52 G.

RESIDENT SEQUENCING I DATA TABLES A B c D PRE- ;PRocEss ANALOG INPUTS A B c I n2 I I /7I4 REsIDENT LOcAL CONTROL A B c D TURBINE CONTROL DATA TABLES cONTROL T R POST \PROCESS FIG. 22 l 623 5229132 624 ,626 I. CCIS 2. ANALOG INPUTS STORE IN USE STORED DATA 3. TuRBINE TABLE MASTER LOGIC TO EvALuATE c. RESIDENT TABLE SEQUENCE Lo sIc b.0PIERATOR PANEL INPUTS sAvE Es OUTPUT RESIDENT Y cco s TURBINE TABLE v FIG. l8

US. Patent Nov. 11 1 975 Sheet 18 of 33 3,919,623

ANALOGS CClS 634 PRE- PROCESSOR E I/ I I 1 I I l I v 638 I l 63g TURBD TURB. c TURBB TURB. A RESIDENT RESIDENT RESIDENT I RESIDENT LOGlC 633 5 TABLE TABLE TABLE TABLE PROGRAM TABLE READ ONLY READ ONLY READ ONLY READ ONLY I I I I j I l I POST- \-P T R oPERAToR ROCESSO PANEL I PROGRAMS I i I Y I ccos FIG. l9 

1. A gas turbine electric power plant comprising a gas turbine having a compressor and combustion and turbine elements, a generator having a field winding and being coupled to said gas turbine for drive power, a fuel system having plural subsystems for supplying one or more fuels to the gas turbine combustion elements, means for exciting said generator field winding, means for cooperatively operating each of said fuel subsystems to energize said turbine and for controlling said exciting means, a control system for developing one or more fuel system control signals, said control system including a digital computer, an input/output system therefor, and associated external circuit means, said circuit means comprising at least fuel system control signal ratioing means having one or more circuit parameters capable of continuous variation, means for operating said computer to determine a total fuel demand signal value and a time varying ratio of individual fuels necessary to continuously satisfy said total fuel demand while changing from operation on one of said fuels to operation on another of said fuels, and means for developing a fuel demand signal corresponding to said determined total fuel demand value and for applying said signal across said fuel signal ratioing means to derive individual control inputs to each of said plural fuel subsystem operating means.
 2. A gas turbine electric power plant as set forth in claim 1 wherein said signal ratioing means comprises a digital potentiometer.
 3. A gas turbine electric power plant as set forth in claim 2 wherein one of said plural fuel subsystems schedules a gaseous primary fuel and another of said plural subsystems schedules a liquid secondary fuel.
 4. A gas turbine electric power plant as set forth in claim 3 wherein said computer operating means automatically initiates ratioing of said primary and said secondary fuel on partial or total failure of said primary fuel supply.
 5. A gas turbine electric power plant as set forth in claim 3 wherein said plant further comprises an operator''s control panel having plural fuel system operating mode selection means thereon for selecting operation on either said primary or said secondary fuel over a first interval of turbine operation, and for selecting automatic transfer to the other of said fuels on the occurrence of one or more predefined events.
 6. A gas turbine electric power plant as set forth in claim 5 wherein said operator''s control panel further provides means for indicating a desired ratio of primary and secondary fuels to sustain gas turbine operation over a second time interval and wherein automatic fuel mixing is provided on the occurrence of one or more predefined events.
 7. An electric power plant as set forth in claim 1 wherein There are additionally provided a plurality of sensors disposed to monitor selected turbine parameters, said plurality of sensors comprising at least an arrangement of fuel pressure sensors, said plurality of sensors providing control system inputs representative of said turbine parameters and wherein said computer operating means determines said total fuel demand and said time varying ratio of individual fuels in response to time varying combinations of said sensor inputs, each of said combinations comprising at least an input from said fuel pressure sensors.
 8. An electric power plant as set forth in claim 7 wherein said computer operating means operates to determine control actions for simultaneous implementation by said plural fuel subsystem operating means to maintain gas turbine operation over a predefined range of exhaust temperatures, over at least one interval of gas turbine operation.
 9. An electric power plant as set forth in claim 8 wherein means are provided for detecting generator load and said computer operating means further provides for controlling said plural fuel subsystems operating means in response to detected load to regulate the generator load substantially to a predetermined value. 